1. Field of the Invention
The present invention relates generally to valves, and more particularly but not exclusively to check valves for cooling mechanisms.
2. Description of the Background Art
Enclosures for housing electronic circuits typically include one or more cooling mechanisms to maintain the circuits at an acceptable operating temperature. In the case of mission-critical equipment, such as a data center network switch or enterprise computer system, the cooling mechanism advantageously includes redundant components so that the equipment does not overheat even if one of its cooling components fail. For example, some equipment designs include multiple axial fans and/or blowers (hereafter referred to as fans when referring to both types) to ensure that there are a sufficient number of remaining functional fans in the enclosure to provide cooling in the event that one of the fans fail.
A cooling mechanism with multiple fans typically includes a plenum arrangement through which the fans draw air through the equipment. When one of the fans fail, reverse airflow through the failing fan results in a reduction of airflow through the plenum, thereby increasing the operating temperature of the equipment. This condition may lead to overheating.
As is well known, a check valve limits flow in one direction. Check valves have been employed to help minimize the negative impact of a failed fan in a plenum arrangement having multiple fans. However, these check valves are typically designed to work only on the exhaust side of an axial fan, occupy significant space outside the fan during normal operation, or can usually only be used with an axial fan. For example, because of their design, some of these check valves are not suitable for use with blowers.
The present invention relates to check valves. In one embodiment, a check valve includes an outer region and a central region. One or more cuts wind from the outer region towards the central region. In the presence of flow along one direction, the check valve opens by extending the central region away from the outer region. In the presence of flow in the reverse direction, the check valve closes by retracting the central region towards the outer region.
These and other features and advantages of the present invention will be readily apparent to persons of ordinary skill in the art upon reading the entirety of this disclosure, which includes the accompanying drawings and claims.